On the main F5 page, I needed a way to adjust the CSS properties on the menu based on what is in a content page.  Enter ASP.NET literals.  Essentially a literal lives up to its name… it allows you to define literal html.

So, in the master I have:
<asp:Literal ID="lit_About" runat=server Text='<li>About</li>' />

How do I manipulate that to trigger the proper CSS class you ask?  By doing this in the code behind on the content page:
protected void Page_Load(object sender, EventArgs e) { Literal menucontrol = Page.Master.FindControl("lit_About") as Literal; menucontrol.Text = "<li class='active'>About</li>"; }